1. Field of the Invention
The present invention relates to an apparatus that trails along with moving machinery and accommodates hose, cable or similar flexible supply lines required by the machinery to operate, and more particularly, to a cable handling system used in longwall mining operations.
2. Background Art
Longwall mining machines used in the mining industry require flexible cables and hoses, hereinafter referred to collectively as "flexible members". Longwall mining machines include a movable shearing machine. The flexible members trail behind the shearing machine and supply electric power, water and hydraulic fluid required for operation of the shearing machine. The longwall mining machines include cable handling systems that protect the flexible members from the harsh conditions attributed to mining and allow them to move along with the moving mining machine.
Usually moving mining machines are integrated with systems that have conveyors to move the mined material. These systems include cable guides or cable handlers as the cable handling system. The cable guide allows the flexible members to be guided along the conveyor as the flexible members trail the moving mining machine during mining operations. The cable handler retains and protects the flexible members as the cable handler moves along with the moving mining machine during mining operations. The following patents are examples of cable guides and cable handlers developed for longwall mining: U.S. Pat. Nos. 3,367,718; 3,861,751; 3,997,039; 4,103,974; 4,119,348; 4,185,874; 4,391,471; 4,458,950; 4,483,567; 4,514,011; 4,545,621; and 4,564,241.
FIGS. 1-3 show a Mansign center pull nylon cable handler 8 made by American Longwall Mining Corporation of Abingdon, Va. This cable handler is an industry standard. The Mansign cable handler 8 includes a flexible chain 10 made of nylon links 12. Links 12 are interconnected to each other by bolts 14. Each link 12 has a male end 16 for connecting with a female end 18 of an adjoining link 12. Each link 12 includes spaced apart parallel extending tips 20 and 20' integrally formed as part of link 12. Tips 20 and 20' extend outwardly from a center 22 of link 12. Flexible members 24 are positioned between tips 20 and 20' and are positioned on opposite sides of center 22. Tips 20 and 20' protect flexible members 24 from damage. A tempered spring steel clip 26 is secured to each link 12 to retain one of the two flexible members 24 (of which only one is shown) to link 12. The side of link 12 on which the steel clip 26 is positioned alternates with respect to adjacent links 12 in chain 10 as shown in FIG. 1.
Although the Mansign cable handler overcomes many of the known problems of earlier cable handler designs, it still has disadvantages. First, tips 20 and 20' tend to break off easily from center 22 during mining operations. Therefore, the cable handler cannot protect the exposed flexible member 24 where a tip 20 or 20' breaks off. Once one of the tips 20 or 20' breaks off from a link 12, that broken link 12 must be replaced by a new link 12. In order to replace the broken link, the respective steel clip 26 must be removed. Then male end 16 and female end 18 of broken link 12 must be unbolted from each adjoining link 12; a new link 12 must be inserted in its place; and steel clip 26 must be replaced. This results in expensive and time consuming procedures. A second disadvantage of the Mansign cable handler is that all of the links 12 must be replaced when changing the outer dimensional size of one of the flexible members or when adding more flexible members that the current links 12 cannot accommodate.
Therefore, it is an object of the present invention to provide a cable handling system having links that can be easily repaired when a tip breaks, thereby reducing the downtime and expense of repairing a cable handling system.
It is another object of the present invention to provide a cable handling system that can be reconfigured for the number of flexible members or the cross sectional size of the flexible members that each link can retain without replacing all of the links, thereby reducing the downtime and expense of a cable handling system during its reconfiguration.